Vania



(No Model.)

H. N. POTTER. METHOD OF AND MEANS FOR SYNGHRONIZING ALTERNATING CURRENT MOTORS 0R GENERATORS.

No. 529,461. Patented Nov. 20, 1894.

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I'IENRY NOEL POTTER, OF ALLEGHENY, ASSIGNOR TO THE WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF PITTSBURG, PENNSYL- VANIA.

METHOD OF AND MEANS FOR SYNCHRONIZING ALTERNATlNG-CURRENT MOTORS OR GENERATORS.

SPECIFICATION forming part of Letters Patent No. 529,461, dated November 20,1894. Application filed May 8,1394:- Serial No. 509,867. (No model.)

To aZZ whom it may concern.-

Be it known that I, HENRY NOEL POTTER,

a citizen of the United States, residing in Allegheny,in the county of Allegheny and State of Pennsylvania, have. invented a new and useful Improvement in Methods of and Means for Synchronizing Alternating-Current M0- tors or Generators, (Case N o. 593,) of which the following is a specification.

My invention relates to a method and means whereby alternating current motors or generators may be synchronized before connect ing them in circuit with each other.

The object of my invention is the provision of a form of synchronizing device or synchronism indicator, which shall appeal to the ear of the operator, so that his eye need not be taken from the machine and switches, and so that the indicator may be placed in any desired situation with respect to the motors or generators to be" synchronized and to the switch whereby they are thrown in circuit.

My invention depends upon the interferonce or coincidence of the magnetizing effects 2 5 of two circuits derived from the circuits to be connected when in synchronism. In the practice of my method these magnetizing effects are made to act upon a single magnetic motorpole, and my invention is thus distinguished 0 from that form of audible synchronizer wherein two motor-poles are formed, and wherein the mechanical interference of these two poles is relied upon to indicate the condition of the two circuits.

My invention is illustrated in the accompanying drawing which is a diagrammatic representation of my synchronizer, showing the method of making connections with the circuits to be connected.

My invention may be used in synchronizing a generator and a motor, or two generators. In either case the mode of operation will be the same, and therefore only one case need be specifically described herein.

Suppose that, in the drawing, the generator is shown at 1 and the motor to be synchronized therewith is shown at 2, the switch for connecting them being shown at 3. The motor 2 will be started by some exterior power, and willbe made togain speed until its counter electromotive force is equal to that of the generator, and its speed approximately the same as that of the generator. This is the time when the switch 3 must be thrown, after which the motor 2 will continue to run under the influence of the generator current.

It is this moment which it is the object ofmy indicator to determine by certain audible effects. For convenience this moment will be called the moment of synchronism hereinafter.

My synchronism indicator consists of a double path for magnetic lines of force, producing but one pair of poles. A portion of this double path is formed by a paramagnetic diaphragm and the whole has generally the relation of parts shown in the drawing, wherein the diaphragm or vibrating body is shown at 4, and the rest of the circuit which is more massive, and is stationary, is shown at 5. The double magnetic circuit is indicated by dotted lines, and one magnetic pole is formed at the middle of the Vibrator or diaphragm, while the other pole forms at 6. This I term the motor pole, as it is itself stationary and simply causes movement of the diaphragm. The double magnetic circuit is produced by the two coils, 7 and 8, which are respectively connected with the motor and the generator circuits, on'the two sides of the switch. It will now be seen that, supposing the proper time to have come for throwing the switch, as defined above, the two coils will be simultaneously producing equally strong magnetic fields of force, and these fields will vary together from one maximum to the other. Now if the direction of magnetization of the two coils, 7 and 8, be opposite, as indicated in the drawing, they will neutralize each other, and there will be no movement of the diaphragm. On the other hand, if the directions of magnetization agree, the time for throwing the switch will be marked by a maximum of vibration of the diaphragm, 4, which will approach to or recede from the pole 6 as the combined 5 magnetisms increase and decrease. Whether,

therefore, silence or maximum sound is to indicate the time for throwing the switch will depend upon the way in which the two coils 7 and 8 are connected to their respective circuits.

Assuming the relation of magnetizations indicated by the arrows in the drawing herewith, the mode of operation of my invention will be as follows: As the motor is being started up, its periods of alternation will of course be slower and its electromotive force less than these elements in the circuit from the generator. There will result from this, a vibration of the diaphragm 4 due to the resultant of the two magnetisms which conform to the resultant of the two electromotive forces at any time. As these resultants necessarily amount at certain times to zero, there will be produced an acoustic effect known as beats,

and shapes of device may be devised, all carrying out the spirit of my invention.

What I claim is- 1. The method herein described of indicat ing the moment of synchronism between two machines, which consists in producing two magnetic circuits by the action of two electric circuits due to the respective electromotive forces of the two machines, said circuits having a common motor-pole as described, and subjecting a single body capable of vibration by magnetism to the influence of said motorpole, substantially as described.

2. In asynchro nism indicator,a diaphragm, a magnetic core or cores presenting a single motor-pole thereto, and vtwo coils connected to the terminals of the machines to be synchronized, said coils being so wound on said core or cores as to produce a resultant effect at said motor-pole, substantially as described.

In testimony whereofl have hereunto subscribed my name this 30th day of April, A. D. 1894.

HENRY NOEL POTTER.

WVitn esses:

J AMES WM. SMITH, HAROLD S. MACKAYE. 

